Honda sent two of NSX into the Japanese GT Car Championship in 1997. The original monocoque made of aluminum was reinforced by roll cage, and most parts of the body shell, such as front hood, fenders and doors were replaced by carbon fiber for its light-weighted. However in 1998, four of NSX were sent into Suzuka circuit.

The NSX was refined again based on high-downforced, lower-weighted and improvement of maintenance. For example, front wing was modified, and fins on both sides of the bumper were added. In addition, rear wing was large-sized with sub-wings to the end. Also its shape from rear fender to rear side was aerodynamics-designed. Another reason why Mobil 1 NSX had high-speed and its stability was its power plant. The engine mount was lowered 15mm by changing its layout. Then 3.5 V6 DOHC powerplant still obtains its power although the race regulation was more strict. The brakes were reinforced by large-sizing its rotor and changing caliper to Brembo-made from AP-made.

Mobil 1 NSX managed by formerly F1 driver, Satoru Nakajima gained second place on an opening race at Suzuka circuit. Furthermore it gained first row on the second race at Fuji circuit. The top speed of straight was higher than any of turbo-charged cars even though NSX was a non-turbocharged car. This Mobil 1 NSX played an important role not only as Honda racing team but also as Japanese car.